qmmp: 1.1.10 -> 1.2.0

Fixes build failure since recent merge of staging branch:

$ nix-build -A qmmp
[...]
AutoMoc error
-------------
Included moc files with the same name will be generated from different sources.
Consider to
 - not include the "moc_<NAME>.cpp" file
 - add a directory prefix to a "<NAME>.moc" include (e.g "sub/<NAME>.moc")
 - rename the source file(s)
Include conflicts
-----------------
"moc_hotkeymanager.cpp" included in
 - "/tmp/nix-build-qmmp-1.1.10.drv-0/qmmp-1.1.10/src/plugins/General/hotkey/hotkeymanager_win.cpp"
 - "/tmp/nix-build-qmmp-1.1.10.drv-0/qmmp-1.1.10/src/plugins/General/hotkey/hotkeymanager_x11.cpp"
would be generated from
 - "/tmp/nix-build-qmmp-1.1.10.drv-0/qmmp-1.1.10/src/plugins/General/hotkey/hotkeymanager.h"
 - "/tmp/nix-build-qmmp-1.1.10.drv-0/qmmp-1.1.10/src/plugins/General/hotkey/hotkeymanager.h"

make[2]: *** [src/plugins/General/hotkey/CMakeFiles/hotkey_autogen.dir/build.make:58: src/plugins/General/hotkey/CMakeFiles/hotkey_autogen] Error 1